The present disclosure relates to films, sheets, and other thin walled products having improved scratch resistance. These products include additives that can be used to crosslink polymers, such as polycarbonate polymers, for improved properties. Also included are compositions including such additives, as well as products (e.g. molded or extruded articles, sheets, films, profiles, etc.) formed from such compositions.
Polycarbonates (PC) are synthetic engineering thermoplastic resins, and are a useful class of polymers having many beneficial properties. Polycarbonate resins are both strong and transparent, and are used for a number of different commercial applications, including electronic engineering (E&E) parts, mechanical parts, graphic and decorative parts, etc.
Polycarbonate polymers/resins and blends containing polycarbonate polymers exhibit flame retardance properties. However, such polymers drip when exposed to a flame, and this behavior worsens as the wall thickness decreases. This behavior greatly diminishes their use in transparent and opaque thin wall applications where a V0 or 5VA flame retardance rating is required. These polymers also have relatively poor chemical resistance and are easy to scratch. It would be desirable to provide additives that can improve these properties.
One way to achieve better scratch resistance and chemical resistance is to post-coat polycarbonate components with a coating that when cured crosslinks and provides the desired performance. The coating forms a bonded hard layer on the surface and has a thickness typically from 3 micrometers (μm) to 18 μm. Examples of such hard coats include acrylate hard coats that are either ultraviolet (UV) or thermally curable, silicone hard coats with acrylate primers, polyurethane hard coats, and melamine hard coats. However, an extra post-production coating step is required to apply and cure these coatings to the polycarbonate film surface. It would be desirable to eliminate this extra step.